Obtain a CBC and sedimentation rate.

Anemia is associated with chronic renal failure. A hemolytic anemia, leukopenia and thrombocytopenia may be associated with lupus. The sedimentation rate is usually high in lupus. A microangiopathic hemolytic anemia and thrombocytopenia is seen with hemolytic-uremic syndrome.

Obtain a urinalysis.

The presence of protein in the urine associated with hematuria is more likely to indicate significant renal disease. Casts in the urine may help determine the underlying cause of the hematuria. Red cell casts are seen in acute post-infectious glomerulonephritis. Hyaline casts may indicate proteinuria. Broad, granular casts may indicate chronic glomerulonephritis.

Send spot urine for creatinine, protein and calcium.

A high protein/creatinine ratio (>0.2) may indicate glomerular disease. A high calcium/creatinine ratio (>0.2) can indicate hypercalciuria that is associated with hematuria.

Obtain serum levels of electrolytes, BUN, creatinine, albumin, calcium, phosphorus and uric acid.

This will give an estimate of renal function.

Have the patient collect a 24-hour urine.

Measure creatinine clearance, and protein, calcium and uric acid excretion rates. One can then obtain a more accurate measure of renal function, and protein losses and the excretion rates of calcium and uric acid. The calcium/creatinine ratio or the protein/creatinine ratio should be suggestive.

Titers to look for streptococcal infections such as ASO and anti-DNase B are warranted when a post-infectious glomerulonephritis is suspected.

They are elevated in acute post-infectious glomerulonephritis. They may sometimes be elevated in Henoch-Schönlein purpura.

A renal imaging study is sometimes useful.

A renal ultrasound is usually sufficient. More sophisticated studies may be indicated depending upon the circumstances. For example, a non-contrasted spiral CT of the abdomen may be warranted if a stone is strongly suspected.

Clotting studies may be obtained.

Hemolytic uremic syndrome may be associated with prolonged clotting studies. Lupus may be associated with abnormal clotting studies.

Obtain an ANA panel and complement levels if lupus is suspected. 

Both may be abnormal in lupus. Complement levels may be low in acute post-infectious glomerulonephritis and membranoproliferative glomerulonephritis.

Obtain a renal biopsy if glomerular disease is suspected.

The exact diagnosis is needed for prognosis and/or therapy Be sure that you can get immunoglobulin staining and electron microscopy as well as routine staining.

Set-up a schedule for follow-up and a plan to refer if indicated.

Microscopic hematuria alone is usually not an indication for a renal biopsy.